2.07 Cytoskeleton Flashcards
0
Q
Provides rigid physical support for certain parts of cells
A
Cytoskeleton
1
Q
Extensive intracellular network of filamentous structures extending throughout the cytoplasm
A
Cytoskeleton
2
Q
Physical support for certain parts of cells
A
Intracellular scaffolding
3
Q
Function of cytoskeleton
A
Structural support
Cell motility
Cell regulation
4
Q
Stabilize and balance opposing forces
Spherical/partially spherical shell structure of lattice shell based on a network of great circles on the surface of a sphere
A
Geodesic dome
5
Q
Changes in cell location and limited movements of parts of the cell
A
Motility
6
Q
Transmit mechanical signals that rearrange the nucleoli and other structures
A
Cell regulation
7
Q
3 main types of cytoskeletal fibers
A
Microtubules
Microfilaments
Intermediate filaments
8
Q
Types of cytoskeleton can be distinguished
A
Biochemically
By TEM
9
Q
Contain alpha and beta tubulins
Grow or shrink as more tubulin molecules are needed or removed
A
Microtubules
10
Q
Important for directing intracellular traffic
Motor molecules also carry vesicles or organelles to various destinations along monorails provided by cytoskeleton
A
Polarity
11
Q
Function of microtubules
A
Mitosis spindle
Intracellular trafficking of vesicles
Cilia and flagella
Axoplasmic flow of materials along neuronal processes
12
Q
Locomotory cells
A
Kinesins
Dyneins
13
Q
Central structural supports in cilia and flagella
A
Microtubules
14
Q
Move unicellular and small multicellular organisms by propelling water past the organism
Move fluid over a surface if anchored on large structures
A
Microtubules
15
Q
Move more like oars with alternating power and recovery strokes
A
Cilia
16
Q
Cilia generate force ______ to the axis of the cilia
A
Perpendicular
17
Q
Undulatory movement
A
Flagella
18
Q
Flagella
Eukaryotic
A
Undulating, wave-like, sinusoidal
19
Q
Flagella
Prokaryotic
A
Rotatory
20
Q
Only vertebrate cell that has flagella
A
Sperm
21
Q
Both cilia and flagella have the same ________ arrangement
A
9+2 pattern
22
Q
Bending of cilia and flagella is driven by the arms of a motor protein _____
A
Dynein
23
Q
Drugs that inhibit microtubules
Anti - gout
A
Colchinine
24
Disrupts microtubules that facilitate the movement of WBC towards the site of inflammation to lessen inflammation
Colchicine
25
Drug that inhibit microtubules
| Anti-fungal
Griseofulvin
26
Inhibit cellular division of fungus
Griseofulvin
27
Drug that inhibit microtubules
Chemotherapeutic agents
Stopping the mitosis of cancer cells
Vinbalstine
| Paclitaxel
28
Rare generic disorder characterized by immobile cilia of the respiratory tract and the Fallopian tubes or sperm flagella
Kartagener Syndrome
| Primary ciliary dyskinesia
29
Immobile cilia
Infertile
Dynein-deficient
Kartagener Syndrome
| Primary ciliary dyskinesia
31
Forms microfilaments
Actin
32
Causes the bending of the cilia and flagella
Dynein
33
Monomeric globular
G-actin
34
At physiologic ionic strength and in the presence of magnesium, G-actin ____ noncovalently to form an insoluble double helical filament
Polymerizes
35
Has a pitch or repeating structure every 35.5 nm
F-actin
36
Function of microfilament
Resist tension
| Form a 3D network
37
The shape of the microvilli in the intestinal cell are ____, anchored to a network of intermediate filaments
Supported by microfilaments
38
Thicker filaments composed of a motor protein, _____, interdigitate with the thinner actin fibers
Myosin
39
In other cells, less organized ____ cause localized contraction
Actin-myosin aggregates
40
Contracting belt of microfilaments divide the cytopalsm of animal cells during the cell division, also termed as ____
Cytokinesis
41
Localized contraction also drives ______, in which pseudopodia extend and contract through the reversible assembly and contraction of actin subunits into microfilaments
Amoeboid movement
42
Clathrin-mediated endocytosis, also referred to as _____, occurs at a membrane indentions where the triskeion-shaped protein clathrin accumulates
Receptor-mediated endocytosis
43
Filaments with an axial periodicity of 21 nm and a diameter of 8-10 nm that is intermediate between the other two
Intermediate filaments
44
More stable and permanent fixtures of the cytoskeleton than the other two classes
Intermediate filaments
45
Functions of intermediate filaments
Bearing tension
Reinforce cell shape and fix organelle location
Relatively stable components of the cytoskeleton
Rather deformable proteins that can be stretched severla times their initial length
46
Most types of IF are cytoplasmic, ____ are nuclear
Lamins
47
Cell-cell adhesion
Desmosomes
48
Cell-matrix adhesion
Hemidesmosomes
49
At the cell membrane, some keratins interact with ____ and ____ via adapter proteins
Desmosomes; hemidesmosomes
50
Distribution of IF
| Lamins
Nuclear lamina
51
Distribution of IF
| Keratins
Epithelial lining, hair, nail (Type I-acidic)
52
Distribution of IF
| Desmin
Muscle
53
Distribution of IF
| Vimentin
Various mesenchymal cells
54
Distribution of IF
| Glial fibrillary acid protein
Glial cells
55
Distribution of IF
| Peripherin
Neurons
56
Distribution of IF
| Neurofilaments (Low, High, Medium)
Neurons
57
Two diseases due to abnormalities in IF
Hutchinson-Gilford Progeria
| Epidermolysis Bullosa Simplex
58
Important for structural scaffolding of the nucleus
Lamin A
59
Mutations in the gene encoding ____ and ____ causes Hutchinson-Gilford Progeria
Lamin A and Lamin C
60
Hutchinson-Gilford Progeria
| Appearance of ____
Accelerated aging
61
Mutations in genes encoding _____ causes epidermolysis bullosa simplex
Various keratins
62
In epidermolysis bullosa simple, there is a diminished capacity of various layers of the skin to resist mechanical stresses due to abnormalities in keratin structure as manifested by _____
Blistering
63
Hollow tubes, wall with 13 tubulin molecules
MIcrotubules
64
Fibrous proteins supercoiled into the thicker cables
Intermediate Filaments
65
2 intertwined strands of actin
Microfilaments
66
```
Maintain cell shape (tension bearing elements)
Changes in cell shape
Muscle contraction
Cytoplasmic streaming
Cell motility and division
```
Microfilament
67
Maintain cell shape (compresion-resisting girders)
Cell motility
Chromosome movement in cell division
Organelle movement
Microtubules
68
Maintain cell shape
Anchorage of nucleus and other organelles
Formation of nuclear lamina
Intermediate filaments
69
Most mammalian cells are located in tissues surrounded by a complex _____, which is a major component of connective tissue
ECM
70
ECM is a _____ component present within all tissues and organs
Noncellular
71
ECM initiates crucial biochemical and biomechanical required for tissue ____, ____ and ____
Morphogenesis, differentiation, homeostasis
72
Functions of ECM
```
Structural support
Compartmentalize tissues
Provide rigidity
Signaling
Highway for cell migration during development, in normal tissue maintenance, and in injury or disease
```
73
Composition of ECM
Water, protein, polysaccharide
74
3 major classes of biomolecules (ECM)
Structural proteins
Specialized proteins
Proteoglycans
75
Most abundant protein in animals
Collagen
76
Collagen has _____ structure containing three alpha-polypeptide chains arranged in right-handed supercoil
Triple helix
77
3 AA for collagen
Glycine, proline, hydroxyproline
78
Types of Collagen
```
Fibril-forming
Network-forming
Fibril-associated collagen with interrupted triple helices
Anchoring
Beaded-filament forming
```
79
Continuous, regular arrangement results in characteristic D period of 67nm
Fibril-forming collagen
80
Examples of fibril forming collagen
I, II, III, V, VI
81
Forms network in basement
Collagen IV
| Network-forming collagen
82
Molecular sieving
| Molecular filtration
Network-forming
83
Examples of network-forming collagen
Type IV, VII, X
84
Short collagens with interruptions
| Linked to collagen II and carries a GAG chain
Fibril-associated collagens with interrupted triple helices
85
Found at the surface of fibril-forming collagen
Fibril-associated collagens with interrupted triple helices
86
Examples of FACITs
IX, XII, XIV
87
Provide functioning integrity by connecting epithelium to stroma
Anchoring collagen
88
Example of anchoring collagen
Type VII
89
Form structural links with cells
| Type VI
Beaded-filament forming
90
Collagen type
| Reticulin
Type III
91
Collagen type
| Cartilage
Type II
92
Collagen type
| Basement membrane
Type IV
93
Collagen type
| Bone
Type I
94
Collagen synthesis
| Undergoes _____ before becoming part of the extracellular collagen fiber
Posttranslational modification
95
Precursor of collagen
Preprocollagen
96
Cardinal principle in the biosynthesis of collagen
Self-assembly
97
Important cofactor in the hydroxylation of selected proline and lysine
Vitamin C
98
Once formed, collagen is metabolically stable. Breakdown of which is increased during _____ and ____.
Starvation
| Inflammatory States
99
Excessive collagen deposition in the liver fibrosis due to prolonged injury to the tissue
Hepatic cirrhosis
100
Collagen defects
| Collagen I
Osterogenesis imperfecta
101
Collagen defects
| Collagen I and V
Ehlers Danlos syndrome
102
Collagen defects
| Collagen IV
Alport Syndrome
103
Collagen defects
| Collagen III
Certain arterial aneurysms
104
Collagen defects
| Collagen VI
Ullrich muscular dystrophy
105
Reticulin fibers cannot hold integrity of your vascular structures
Certain arterial aneurysms
106
Collagen defects
| Collagen IX and XI
Certain chondrodysplasias
107
Bone fragility, short stature, bone deformities, teeth abnormality, gray-blue sclera, hearing loss
Osteogenesis Imperfecta
108
Osteogenesis imperfecta is caused by mutatation in either type I collagen ______
COL1A1 or COL1A2
109
Liver spots on skin, spongy gums, bleeding from mucous membane, depresion, immobility
Scurvy
110
____ is required for prolyl hydroxylase and lysyl hydroxylase activities
Ascorbate
111
Elastin is important in ____ and _____ in tissues
Extensibility and elastic recoil in tissues
112
Exhibits a variety of random coil conformations that permit _____ and ____
Stretch and subsequent coil
113
Large glycoproteins whose primary structures are dominated by cbEGF domains that in the presence of calcium, adopt a rodlike structure
Fibrillin
114
Structural component of microfibril
| Secreted ECM by fibroblasts and becomes incorporated into the insoluble microfibrils
Fibrillin-1
115
Provide a scaffold or deposition of elastin
Microfibril
116
Caused by dominant fibrillin-1 mutations
Skeletal, ocular, cardiovascular defects
Deficiency of elastin-associated microfibrils
Marfan syndrome
117
Syndrome that may result from alterations in cell signalling
Marfan syndrome
118
Hyperaerated lung
| Damage to the lung air sacs that affects breathing
Emphysema
119
Increased alveolar size reduces the surface area for gas exchange
Emphysema
120
Elastic fiber biogenesis
Assembly of microfibrils >> association of tropoelastin aggregates with the microfibrils >> crosslinking of tropoelastins with each other by _____ to form polymers
Lysyl oxidase
121
Primary protein component of the basal lamina
Laminin, entactin, type IV collagen
122
Basement membranes are involved in a multitude of biological processes: __, ___, ___
Cell proliferation
Cell differentiation
Cell migration
123
Maintain cell polarization and organization as well as tissue structure
Basement membrane
124
Basement membrane acts as _____ in the kidney between vasculature and the urinary space
Filtration barrier
125
Laminins
| 3 elongated polypeptide chains (A, B, B2) linked together to form _____
Elongated cruciform shape
126
Binding site for type IV collagen, heparin, integrins on cell surface
Laminin
127
Assemble into trimers in the ER and are secreted as trimers intro extracellular space
Laminin Trimer Polymerase
128
Full-sized laminin trimers can ____ into a macromolecular network through a short-arm interactions
Self-polymerize
